Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
There is provided a technique that employs a dedicated heater to eliminate condensation inside a document reading unit for an image reading apparatus such as a copier and a multi-functional peripheral.
For example, there is proposed an original document reading apparatus in an image forming apparatus that includes: a gain adjustment unit that outputs adjusted data, which is a gain-adjusted analog signal from a photoelectric conversion unit, an reading unit that reads the output adjusted by the gain adjustment unit, and a control unit that determines whether or not condensation occurs from a chronological change of the read adjusted output value, so as to control a condensation-preventing heater based on the determination. This ensures precise detection of the condensation without using a specific unit while reducing energy required for the condensation prevention and a cost of an apparatus.